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< Earlier Kibitzing · PAGE 3 OF 3 ·
Later Kibitzing> |
| Aug-17-12 | | Conrad93: This should have been obvious considering the threat of mate. Now I feel like an idiot. |
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| Aug-17-12 | | psycho path: I see the weak square on F6 and G7
but can someone explain this move to me:
26. bXC4 for blacks response why not bxC4!! why not take with the pawn instead of the queen? |
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| Aug-17-12 | | Sularus: <psycho path><26. bXC4 for blacks response why not bxC4!! why not take with the pawn instead of the queen?> Because it does not matter. White will still play 27. Qf6 |
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| Aug-17-12 | | Zatrikion: Black K is seriously cornered due to h6 pawn and the f6 weak square. All white have to do, is prevent the black Q from capturing on e5, so: 25.Nd5 (double threat, Nxe7 and Qf6)
25..Qxd5
26.Bxc4 Qxc4
27.Qf6 1-0
However, black can avoid mate with:
25..f5
26.Nxe7 Qxe7
27.Qxd4
White is up a pawn and the exchange. |
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| Aug-17-12 | | SpoiltVictorianChild: Wow. That was so subtle that even after seeing the answer it took me 5 minutes to figure out why all the moves were important. |
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| Aug-17-12 | | Zatrikion: <poszvald> Yes, but after white's 25.Bxc4 then black respond with 25..Bxc4. Now, if 26.Qf6 then 26..Qxe5.Black Q is protected by Re7 and white cannot mate with Qg7. Moreover, no material has been gained. |
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Aug-17-12
 | | gawain: I'm feeling stupid today. I do not see why 25 Qf6 does not win for White. I am smart enough to know that this cannot be the solution to a Friday puzzle. What am I missing? I'll check the game and the kibitzing now. |
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Aug-17-12
| | gawain: Oh, I overlooked the 25... Qxe5 defense. Elementary. Need more coffee. |
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| Aug-17-12 | | Overgod: Solved it in 10-15 minutes. The key square is obstructing d5, with the queen forced to take it. Once the bishop then has the clear to take the knight, White has a forced win. Mate is unstoppable, even if black sacs all its pieces to prolong the game... Part of the calculation is to recognize that the white king has safe exit after Qxa2+ followed by Qa5+ and Bc4+, with the white king safe and happy on f2. This was not an easy calculation... Nice puzzle. |
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Aug-17-12
 | | chrisowen: Delve in d5 try cut off queen communication masking e5 provides a mate at g7 line goes something like this 24.nd5 qxd5 26.bxc4 qxc4 27.qf6 and mate is unstoppable except for a few spite checks in seems it g6 as the blunder allowing a pretty finish kind thoughts bestowed upon e5 blocking queen line of sight if any refusal then e7 drops to f5 or a3+ again f5 has to come so black is going exchange down in Alekseevs case tell it hold in qxe5 but plugs g6 and i fear the worst one choices abound even thinking now pg6 doesnt save him as bxh7+ crashing through to disrupt his majesty clinical laced knight resplendid in butchering blacks defence at sea. Dutifuls in sacrifice d5 for space in deflected queen overloaded a f6 you duck and weave. |
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| Aug-17-12 | | kevin86: I went for the immediate Qf6...too bad,it fails to Qxe5. |
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| Aug-17-12 | | bachbeet: Didn't get it. I moved the Q to f6 right away without seeing that Qxe5 eliminates the threat. |
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| Aug-17-12 | | M.Hassan: <johnlspouge:There is nothing wrong with it. Toga evaluates 25.Nd5 at 3.0P, 25.Bxc4 at about 2.5P, and 25.Qf6 at about 1.5P. It's just that 25.Nd5 is the best move - and it's artistic!> Thank you sir: Good explanation and just that I do not have Toga and had to ask that question. |
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Aug-17-12
 | | Once: A cute trick. 25 Nd5 forces black to self-block on d5, which in turn means that he cannot play Qxe5 which in turn means that he cannot stop white from playing the standard Qf6-Qg7 mate. White has two ways to self-block, but as both have been adequately covered there is no need to repeat. But the thing which is puzzling me is why Alekseev played into an obviously lost line. After 25. Nd5, black's sternest defence is surely 25...f5 when we might get something like this: 26. Nxe7+ Qxe7 27. Bxc4 Bxc4 28. Qxd4
click for larger viewWhite is comfortably material ahead (exchange plus a prawn), but we need to be a little careful. Many a game has been drawn from a material deficit if the defender is able to build a fortress or trade down into insufficient mating material. That's why we really need to take a quick peek at this variation. It doesn't take too long to see that white wins comfortably from here. White has an iron grip on the open d file. Whilst his prawns are a little weak (e5 and g5), he has plenty of room for his rooks to work in. I think we can safely call this one for white, although he still has some work to do. So why did black opt for the clearly inferior 25...Qxd5? I can think of a few explanations: 1. The least likely explanation is that Alekseev didn't spot the tactics. He might have missed the strength of 26. Bxc4 and realised that a move like 25...f5 was his only practical chance. Somehow, I can't believe that. Any half decent player (and Alekseev is more than half decent) would spot that 25...Qxd5 is tantamount to resignation. 2. The second possible explanation is that this was clock pressure. Given more than a couple of minutes, Alekseev would surely have noticed that 25...Qxd5 was a poor move. 3. Alekseev may have been paying a compliment to his opponent by allowing him to play his tactic on the board. That was what they used to do a hundred years ago as a sporting gesture. But this is 2007, not 1887. Somewhow I can't see it. 4. There is also what we might call a dead cat bounce. Shocked by his sudden demise, black plays on auto-pilot for a couple of moves before tipping his king. It's a kind of slow-motion death. 5. But my favourite explanation is that black was playing the odds. He knew that his objectively "best" move was 25...f5. But against someone of Karjakin's strength that just leads to a slow death rather than a quick one. So he plays the naive 25... Qxd5 knowing that his only chance was if Karjakin doesn't play the best move. For example, it is just possible that white may have thrown in 26. Qf6? A very slim hope perhaps, but better than no hope. We may never know. It's certainly much easier for us to sit here and spot these variations without the clock ticking, than it is for the GMs who have to do it for real. |
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| Aug-17-12 | | Crispy Seagull: Perhaps a strong player can help me; what is black's response to 25. Bxc4? |
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Aug-17-12
 | | Jimfromprovidence: <Crispy Seagull> <Perhaps a strong player can help me; what is black's response to 25. Bxc4?> Not a strong player but thanks for asking. You can look at my previous post for the details, but 25 Bxc4 is winning for white. |
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| Aug-17-12 | | David2009: Karjakin vs E Alekseev, 2007 White 25? The immediate 25.Qf6 Qxe5 27.Qxe7 dxc3 gives Black excellent counter-play so prepare Qf6 with 25.Bxc4 GOOT! Main
variation: 25...Qxc4 26.b3 GOOT2! seeing 26...Qxc3 Qf6. Time to
check:
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The game ended differently - what have I missed? Here's the puzzle position
click for larger view
with a link to Crafty End Game Trainer: http://www.chessvideos.tv/endgame-t... The perspicacious robot unerringly spots the gaping hole in my analysis: 25.Bxc4 Bxc4! and the Re7 now hits the e5 Pawn, so 26.Qf6 fails to force mate. Back to the drawing board i.e peruse the other kibitzes. I take heart from <Jim>'s post that 25.Bxc4 does indeed win, and duly beat the EGT, starting 25.Bxc4 Bxc4 26.Ne4! Qxe5 27.Qxe5 Rxe5 28.Nf6+ Kh8 29.Nd7 winning the exchange. The stout-hearted robot fights on with 29...Ree8 30.Nxf8 (not 30.Rxd4 Rd8) 30...Rxf8 31.Rxd4 f6 but the material deficit is too great: 32.b3 Bg8 33.gxf6 Rxf6 34.Rhd1 g5 35.Rd6 Rg6 36.Kb2 g4 37.Kc3 g3 38.Rxg6 hxg6 39.Rg1 Kh7 40.Rxg3 Kxh6 41.Kd4 b4 42.c4 bxc3 43.Rxc3 Kg7 44.Rc6 a5 45.Ra6 g5 46.Rxa5 etc. there may be better for either side. Against 25.Nd5 the robot replies 25...f5 which as pointed out by <Zatrikion> loses the exchange and a pawn: 26.Nxe7 Qxe7 27.Qxd4. The robot fights on with 27...f4 and it is getting near my bed time, so Ileae to others the task of finishing off the EGT. Enjoy exploring the variations! |
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| Aug-17-12 | | James D Flynn: My analysis from looking at the position online went
Material is equal but White threatens mate by Qf5 then Qg7. The immediate Qf6 is met by Qxe5 so White needs to either block the path of the Q or remove the defending N on c4 or add a defender tp the e5 square. Candidates Nd5, Bxc4, or Re1(either). If the first move isn�t forcing e.g a win of material or the threat to win material, then Black can take the N on c3 and/or check with the N on a3 or play f5 or Bf5 to block the Q access to f6..
25.Nd5 Qxd5 26.Bxc4 Qxc4 27.b3 d3 28.bxc4 dxc2+ 29.Kxc2 Bf5+ 30.Kb2 bxc4 31.Qxc4 Rb7+ 32.Ka1 Rfb8 33.Qd4 White �s Q defends the b2square and his rooks the b1 square he threatens e6 and mate on g7 if Black defends by Be6 34.R Rb1 forces an exchange of rooks. White is up a Q for a B and his K is quite secure .
25.Bxc4 Bxc4 26.Rhe1 f5( if dxc3 27.Qf6 Bxa2+ 28.Kxa2 and mates on g7.) 27.gxf6 dxc3 28.fxe7 Rxf4 29.e8=Q+ Rf8 30.Qd7 Rf7 31.Qd6 and the Black Q has no good squares to avoid the exchange. White emerges the exchange and a dangerous central passed pawn up.
25.Rde1 f5 26.gxf6 dxc3 27.fxe7 Rxf4 28.e8=Q+ Rf8 29.Qxe6+ Kh8 30.Bxc4 bxc4 31.Qd6nad Black must exchange and remains a R down,
Then I decided to set u the position on a real stauton chess set. I immediately added Qf6 to the list of candidates: 25.Qf6 Qxe5 26.Qxe7 dxc3 27.Bxc4 bxc4 28 Rd8 wins immediately. |
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| Aug-17-12 | | TheBish: Karjakin vs E Alekseev, 2007 White to play (25.?) "Difficult"
White's goal seems to be playing Qf6 and Qg7#, but this isn't as strong if played immediately: 25. Qf6 Qxe5 26. Qxe7 Nd2+ 27. Rxd2 Bxa2+ 28. Kxa2 Qxe7 29. Ne4 and White stands better, but far from convincing. 25. Nd5!
This interferes with the BQ's control of e5. The knight's attack on the e7 rook is secondary. 25...Qxd5 26. Bxc4 Qxc4 27. Qf6 and there is no defense against the mate. |
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| Aug-17-12 | | morfishine: <Jimfromprovidence> Another ingenious line! I always look forward to your posts with much interest! However, having analyzed the same first move [25.Bxc4], I found the problem with <25.Bxc4> is <25...Bf5> and White has two pieces hanging and no fire on the e-file (to protect <e5>).
click for larger viewThis is why I missed it today and feel silly to not identify <25.Nd5> |
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| Aug-17-12 | | Abdel Irada: <Once a knight>
Interference week continues on CG.com.
At first glance, White would like to play 25. ♕f6 to threaten mate on g7. And in fact, this does work, up to a point: After 25. ...♕xe5; 26. ♕xe7, ♘d2†; 27. ♔a1, dxc3; 28. b3!, White has the exchange for a pawn, a small edge but perhaps enough to win. However, White has a far more efficient way to win in 25. ♘d5!. With this interference move, he renews his thematic mate threat in a position in which either capture leaves Black unable to defend: (1) 25. ...♗xd5;
26. ♕f6, ♘a3†/♘d2†;
27. ♔a1  . Without a way to remove his bishop from d5 with gain of tempo, Black won't be able to get his queen to e5 on time to prevent mate. (2) 25. ...♕xd5;
26. ♗xc4 and either
(2.1) 26. ...bxc4;
27. ♕f6 , when Black will have to give up his queen to delay mate, or (2.2) 26. ...♕xc4;
27. b3, ♕ moves;
28. ♕f6 . Again Black can't hold off the mate, although b3 is a necessary intermezzo because the immediate 27. ♕f6? allows a perpetual check. Of course, Black has another option: not to take the knight. However, after 25. ...f5;
26. ♘xe7†, ♕xe7;
27. ♕xd4, White will slowly tighten the noose until Black runs out of air. His demise is slower than the neck-snapping drop-and-jerk that follows either capture on d5, but it is none the less sure. |
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| Aug-17-12 | | Abdel Irada: <On further review...> It appears White can escape the perpetual after all by running off to f2. However, I see no defense after 27. b3 either, so the solution appears to work either way. |
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Aug-18-12
| | Jimfromprovidence: <Morf> <However, having analyzed the same first move [25.Bxc4], I found the problem with <25.Bxc4> is <25...Bf5> and White has two pieces hanging and no fire on the e-file (to protect <e5>).> Morf, thanks for the input. I think the problem with 25...Bf5 is that white can follow with 26 Nd5. 
click for larger viewSo if black plays 26..bxc4 white is up the exchange plus a pawn after 27 Nxe7+ Qxe7 28 Qxd4. 
click for larger viewOn the other hand, if black follows 26 Nd5 with 26...Re6, then white can retreat his bishop to b3 and keep the "piece". 
click for larger view |
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| Aug-18-12 | | morfishine: Good morning <Jimfromprovidence>! I'd love to see <25.Bxc4> work. The problem I was having with 25.Bxc4 Bf5 <26.Nd5> is Black interpolates <26...Bxc2+>
click for larger view
Here, if 27.Kxc2 then 27...Qxc4+ and Black is wiggling free: (28.Kb1 Qxd5 or 28.Nc3 dxc3 29.Qf6 cxb2+ 30.Kxb2 [If 30.Kb1 Qe4+ followed by 31...Qxe5]...Qe2+ 31.K-any Qxe5) At this point, I figured or knew I was on the wrong track for White to win. However, and much thanks for your initiative (which pushed me to see this line through), after 26...Bxc2+ White has the much better <27.Ka1> and Black's tricks are thwarted plus he faces material loss. So yes, I agree <25.Bxc4> wins too, just less elegantly. Its good to see <25.Bxc4> is very strong and winning On the other hand, the immediate <25.Nd5> is cleaner and more 'GM-like' |
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| Aug-18-12 | | nariga: How about:
25. Nd4 Na3+
a) 26. bxa3 Bxd4 will eliminate the threat of white Qf6 as Bxa2+ will open up the black rook in e-column b) 26. Ka1 Qxd5 threatening Qxa2+ etc.
c) Kc1 f5 27. exf6 Ref7 etc. and black seems to be reasonably ok??? |
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< Earlier Kibitzing · PAGE 3 OF 3 ·
Later Kibitzing> |
Kibitzing
sac: 25.Nd5